“She’s very busy,” Bilson told PEOPLE at No Kid Hungry‘s Dinner to End Childhood Hunger at The Four Seasons in Los Angeles on Wednesday.

When asked if her baby girl is active, she doesn’t hesitate to answer. “Literally, she might be an Olympic gymnast next month. She’s crazy,” jokes Bilson of Briar, who celebrates her first birthday on Oct. 29.

When Briar isn’t reveling in her active lifestyle, she enjoys more scholarly pursuits, like reading. “She is very well-read,” says Bilson. “She likes all books. I’m telling you, she’s like Belle from Beauty and the Beast.”

While only the back of the baby girl’s head is visible in the photo, it’s easy to tell she’s a cutie.

In the picture, shared by Bilson, 33, Briar Rose is seen sitting on a blanket in the grass with her father, her tiny hand resting on her knee as he blows bubbles. Her face is covered with a floral bucket hat.

A rep for Bilson denies the report and calls the source’s claim “speculation and gossip.”

Although the mom-to-be and the actor have stayed mum on pending parenthood — and have yet to officially announce they will welcome their first child together — sources confirmed to PEOPLE in May that Bilson was pregnant.

But when Bilson, 32, was spotted walking on a beach in Barbados, she let her belly do all the talking, showing off her bump in a patterned two-piece.

Bilson, 32, hinted at a future family with Christensen, 33, while joking about her age-defying appearance working against her should she get pregnant.

“I’ve always looked young because I’m so short, and especially if I’m dressed down. When I have a baby, everybody’s going to be like, ‘Awww, poor teen mom. Poor girl,’ ” she recently told Health.Read More